#!/usr/bin/env python

## \file direct.py
#  \brief python package for running direct solutions
#  \author T. Lukaczyk, F. Palacios
#  \version 7.1.0 "Blackbird"
#
# SU2 Project Website: https://su2code.github.io
# 
# The SU2 Project is maintained by the SU2 Foundation 
# (http://su2foundation.org)
#
# Copyright 2012-2020, SU2 Contributors (cf. AUTHORS.md)
#
# SU2 is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
# 
# SU2 is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with SU2. If not, see <http://www.gnu.org/licenses/>.

# ----------------------------------------------------------------------
#  Imports
# ----------------------------------------------------------------------

import copy

from .. import io  as su2io
from .merge     import merge     as su2merge
from .interface import CFD       as SU2_CFD

# ----------------------------------------------------------------------
#  Direct Simulation
# ----------------------------------------------------------------------

def direct ( config ): 
    """ info = SU2.run.direct(config)
        
        Runs an adjoint analysis with:
            SU2.run.decomp()
            SU2.run.CFD()
            SU2.run.merge()
            
        Assumptions:
            Does not rename restart filename to solution filename
            Adds 'direct' suffix to convergence filename
                        
        Outputs:
            info - SU2 State with keys:
                FUNCTIONS
                HISTORY.DIRECT
                FILES.DIRECT
                
        Updates:
            config.MATH_PROBLEM
            
        Executes in:
            ./
    """
    
    # local copy
    konfig = copy.deepcopy(config)

    # setup direct problem
    konfig['MATH_PROBLEM']  = 'DIRECT'
    konfig['CONV_FILENAME'] = konfig['CONV_FILENAME'] + '_direct'    
    
    direct_diff = konfig.get('DIRECT_DIFF','NO') == "YES"

    # Run Solution
    SU2_CFD(konfig)

    # multizone cases
    multizone_cases = su2io.get_multizone(konfig)

    # merge
    konfig['SOLUTION_FILENAME'] = konfig['RESTART_FILENAME']
    if 'FLUID_STRUCTURE_INTERACTION' in multizone_cases:
        konfig['SOLUTION_FILENAME'] = konfig['RESTART_FILENAME']

    # filenames
    plot_format      = konfig.get('TABULAR_FORMAT', 'CSV')
    plot_extension   = su2io.get_extension(plot_format)

    # adapt the history_filename, if a restart solution is chosen
    # check for 'RESTART_ITER' is to avoid forced restart situation in "compute_polar.py"...
    if konfig.get('RESTART_SOL','NO') == 'YES' and konfig.get('RESTART_ITER',1) != 1:
        restart_iter = '_'+str(konfig['RESTART_ITER']).zfill(5)
        history_filename = konfig['CONV_FILENAME'] + restart_iter + plot_extension
    else:
        history_filename = konfig['CONV_FILENAME'] + plot_extension

    special_cases    = su2io.get_specialCases(konfig)
    
    # averaging final iterations
    final_avg = config.get('ITER_AVERAGE_OBJ',0)
    # get chosen windowing function, default is square
    wnd_fct = config.get('WINDOW_FUNCTION', 'SQUARE')

    # get history and objectives
    history      = su2io.read_history( history_filename , config.NZONES)
    aerodynamics = su2io.read_aerodynamics( history_filename , config.NZONES, special_cases, final_avg, wnd_fct )
    
    # update super config
    config.update({ 'MATH_PROBLEM' : konfig['MATH_PROBLEM']  })
                    
    # info out
    info = su2io.State()
    info.FUNCTIONS.update( aerodynamics )
    info.FILES.DIRECT = konfig['RESTART_FILENAME']
    if 'EQUIV_AREA' in special_cases:
        info.FILES.WEIGHT_NF = 'WeightNF.dat'
    if 'INV_DESIGN_CP' in special_cases:
        info.FILES.TARGET_CP = 'TargetCp.dat'
    if 'INV_DESIGN_HEATFLUX' in special_cases:
        info.FILES.TARGET_HEATFLUX = 'TargetHeatFlux.dat'
    info.HISTORY.DIRECT = history

    '''If WINDOW_CAUCHY_CRIT is activated and the time marching converged before the final time has been reached, 
       store the information for the adjoint run'''
    if config.get('WINDOW_CAUCHY_CRIT', 'NO') == 'YES' and config.TIME_MARCHING != 'NO':
        konfig['TIME_ITER'] = int(info.HISTORY.DIRECT.Time_Iter[-1] + 1)  # update the last iteration
        if konfig['UNST_ADJOINT_ITER'] > konfig['TIME_ITER']:
            konfig['ITER_AVERAGE_OBJ'] = max(0,konfig['ITER_AVERAGE_OBJ'] -(konfig['UNST_ADJOINT_ITER']-konfig['TIME_ITER']))
            konfig['UNST_ADJOINT_ITER'] = konfig['TIME_ITER']

        info['WND_CAUCHY_DATA'] = {'TIME_ITER': konfig['TIME_ITER'], 'UNST_ADJOINT_ITER': konfig['UNST_ADJOINT_ITER'],
                                   'ITER_AVERAGE_OBJ': konfig['ITER_AVERAGE_OBJ']}

    su2merge(konfig)

    return info
